Search results for "FREQUENCY"

Autosomal microsatellite and mtDNA genetic analysis in Sicily (Italy).

2003

DNA samples from 465 blood donors living in 7 towns of Sicily, the largest island of Italy, have been collected according to well defined criteria, and their genetic heterogeneity tested on the basis of 9 autosomal microsatellite and mitochondrial DNA polymorphisms for a total of 85 microsatellite allele and 10 mtDNA haplogroup frequencies. A preliminary account of the results shows that: a) the samples are genetically heterogeneous; b) the first principal coordinates of the samples are correlated more with their longitude than with their latitude, and this result is even more remarkable when one outlier sample (Butera) is not considered; c) distances among samples calculated from allele an…

The Origins of Lactase Persistence in Europe

2009

Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (−13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the −13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model w…

Data for nine autosomal STRs markers from Valencia (East Mediterranean coast of the Iberian Peninsula)

2000

Nine STRs loci have been typed in a sample from Valencia, a population from the East Mediterranean coast of the Iberian Peninsula.

Molecular Characterization of a Chromosomal Rearrangement Involved in the Adaptive Evolution of Yeast Strains

2002

Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, is the product of a reciprocal translocation between chromosomes VIII and XVI due to unequal crossing-over mediated by microhomology between very short sequences on the 5' upstream regions of the SSU1 and ECM34 genes. We also show that this translocation is only present in wine yeast strains, suggesting that the use for millennia of sulfite as a preservative in wine production could have favored …

2018

In the recent past, sequencing of ancient human genomes has become increasingly common, leading to an immense amount of data to be explored. For this study we focused on comparing a set of ancient individuals with modern populations on behalf of markers for celiac disease. We analyzed a panel of 64 SNPs related to this disease, trying to detect changes in allele frequencies between ancient and modern individuals. We hope to make a contribution to the subject of genetic health throughout human history.

Abstract 571: The shared mutation and neoantigen landscape of MMR-deficient colorectal cancers suggests immunoediting during tumor evolution

2019

Abstract The immune system can recognize and attack cancer cells and their precursors, especially those with a high load of mutation-induced neoantigens. Such neoantigens are particularly abundant in DNA mismatch repair (MMR)-deficient cancers. MMR deficiency results in microsatellite instability (MSI), which leads to multiple insertion/deletion mutations at coding microsatellites and to neoantigen-inducing translational frameshifts. The significance of immune selection and immunoediting potentially shaping the neoantigen landscape during the progression from premalignant MMR-deficient lesions into cancers has not yet been analyzed. We hypothesized that the neoantigen landscape of MSI cance…

Simulating the Influence of Conjugative Plasmids Kinetic Values on the Multilevel Dynamics of Antimicrobial Resistance in a Membrane Computing Model

2020

AbstractPlasmids harboring antibiotic resistance genes differ in their kinetic values as plasmid conjugation rate, segregation rate by incompatibility with related plasmids, rate of stochastic loss during replication, cost reducing the host-cell fitness, and frequency of compensatory mutations to reduce plasmid cost, depending on the cell mutation frequency. How variation in these values influence the success of a plasmid and their resistance genes in complex ecosystems, as the microbiota? Genes are located in plasmids, plasmids in cells, cells in populations. These populations are embedded in ensembles of species in different human hosts, are able to exchange between them bacterial ensembl…

Frequency-dependent selection in human immunodeficiency virus type 1.

2001

Genetic variation is the main evolutionary strategy adopted by RNA viruses and retroviruses. Evolution operates through competition between different individuals in the same environment, resulting in the imposition of the fittest variant. The process of competition could be affected by various factors, including the frequency of the different competing individuals. In order to investigate this aspect, individual virus populations derived from a human immunodeficiency virus type 1 isolate were studied at different competing proportions. The dynamics of variant imposition in each competition experiment permitted the detection of frequency-dependent selection (FDS); i.e. the imposition of vari…

Screening and identification ofvipgenes inBacillus thuringiensisstrains

2009

Aims:  To identify known vip genes and to detect potentially novel vip genes in a collection of 507 strains of Bacillus thuringiensis. Methods and Results:  Following a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy, four restriction patterns were found within the vip1 family: vip1Aa1, vip1Ba1/vip1Ba2 and vip1Ca. In the screening of vip2 genes, patterns similar to those of vip2Aa1, vip2Ba1/vip2Ba2 and vip2Ac1 genes were observed. Patterns for vip3Aa1, vip3Ae2 and vip3Af1 were found among vip3 genes. Two new patterns revealed novel vip1 and vip3A genes. The observed frequency of genes belonging to vip1 and vip2 families was around 10%, whereas 48·9% of…

Second generation sequencing of three STRs D3S1358, D12S391 and D21S11 in Danes and a new nomenclature for sequenced STR alleles

2014

Second generation sequencing (SGS) may revolutionize the field of forensic STR typing. Two of the essential requirements for implementation of an SGS based approach for forensic investigations are (1) establishment of adequate frequency databases and (2) adoption of a new STR nomenclature. We report the STR sequences and allele frequencies of three STR loci: D3S1358, D12S391 and D21S11 in 197 unrelated Danes. We used a new STR nomenclature that depicts the locus name used in forensic genetics, the length of the repeat region divided by the repeat length (typically 4 nucleotides) and detailed sequence information of possible sub-repeats and SNPs within the amplified fragment.